uC Command Line Interface, Part 1 (Updated with sources)

When doing some project which involves a microcontroller I often have to write some test code/script in order to verify correct operation. This is typically a time consuming process. So some time ago, I started working on a small side-project, which would allow me to communicate with a microcontroller directly, either via UART-USB bridge or some other transport protocol. The idea was to basically recreate a unix like shell, where I could control peripherals, via short commands and maybe do some scripting as well and the whole project should be easy to expand and maintain.